The objective of the proposed program is to offer basic science training for investigation of growth and development by supporting students in a joint M.D./Ph.D. program. This is the continuation of a program which has been successfully pursued for over 40 years. The trainees are selected from students already admitted to the Pritzker School of Medicine. At a minimum, they have a Bachelor of Science degree and usually two years of medical school training. They are selected on the basis of demonstrated ability in basic science, indication of devotion to pursuit of a research and teaching career in medicine, and outstanding academic credentials. Selection is carried out by a faculty committee and is based on academic records, recommendations, prior accomplishments, and personal interviews. All students must fulfill the Ph.D. requirements of a particular basic science department or committee of their choosing. A schedule of training is determined for each student so that basic science coursework and research training is integrated between the pre-clinical and clinical phases of medical school. Often, certain of the Ph.D. requirements may be completed during elective periods of the pre-clinical curriculum. Completion of research training occurs before or during the final clinical phase of the M.D. program. Thus the M.D./Ph.D. program is usually completed in five or six years, although the training period supported by this grant is often less than five years. Any intermediate funding is provided by the trainee's mentor, private awards, or institutional funds. Fifteen to eighteen trainees will typically be in the program at any given time, usually allowing admission of two to three new trainees annually. This program attracts outstanding candidates, has had no attrition over a 30-year period, and produces exceptional M.D./Ph.D. graduates who receive acceptance to outstanding residency programs and research fellowship programs. The training of dual-degree professionals contributes in a substantial way to the quality of health care in this country. Since these individuals are trained as both clinicians and researchers, they have a broad perspective and can generate novel approaches to medical issues. Graduates of this program hold major positions in universities, research institutes, the NIH, and pharmaceutical companies. [unreadable] [unreadable] [unreadable]